I have a VB.net application that has been working well. I added an additional function to it and it still works well on my development machine, which uses Windows 7 Enterprise OS. But when I deploy it to the target machine, Windows Server 2008 R2, I get this error message: Operator '-' is not defined for type DBNull. I have attached a screen shot of the message box. Again, I get this error on theServer 2008 machine, but not on the Windows 7 machine.
To my knowledge, I have not DBNull datatypes defined. A search using the Find & Replace function in Visual Studio for DBNull comes up empty.
What can be causing this error? How can I track it down? How can I eliminate it?